The invention disclosed herein relates generally to performing storage operations on electronic data in a computer network. More particularly, the present invention relates to using a replication copy or other copy of primary storage production data for performing storage operations.
Current storage management systems employ a number of different methods to perform storage operations on electronic data. For example, data can be stored in primary storage as a primary copy or in secondary storage as various types of secondary copies including, a backup copy, a snapshot copy, a hierarchical storage management copy (“HSM”), as an archive copy, and as other types of copies.
A primary copy of data is generally a production copy or other “live” version of the data which is used by a software application and is generally in the native format of that application. Primary copy data may be maintained in a local memory or other high-speed storage device that allows for relatively fast data access if necessary. Such primary copy data is typically intended for short term retention (e.g., several hours or days) before some or all of the data is stored as one or more secondary copies, for example to prevent loss of data in the event that a problem occurred with the data stored in primary storage.
Secondary copies include point-in-time data and are typically intended for long-term retention (e.g., weeks, months or years depending on retention criteria, for example, as specified in a storage policy as further described herein) before some or all of the data is moved to other storage or discarded. Secondary copies may be indexed so that users can browse and restore the data at another point in time. After certain primary copy data is migrated to secondary storage, a pointer or other location indicia such as a stub may be placed in the primary copy to indicate the current location of that data.
In conventional storage management systems, a secondary copy is typically produced by performing a storage operation, such as a backup, of production data, such as a primary copy. Creating such secondary copies typically requires taking the production data or primary copy offline so that it is inaccessible or unavailable to a client or other system component. In general, it is preferable to avoid taking a primary copy, and any components associated therewith, offline, however, if it is unavoidable, it is preferable to minimize the duration that the copies or components are offline. Storage operations that require the primary copy are typically scheduled overnight when the primary copy is less likely to be used by a client, which typically accesses the primary copy during daytime hours. Thus, the primary copy may often be unavailable, or access to the primary copy may be difficult to provide because it is frequently in use. In addition, storage management system components using the primary copy for storage operations may also be unavailable to perform other concurrent storage operations. Such systems may encounter bottlenecks in allocation of system resources to perform storage operations.